Automatically-reclosing circuit-breaker



E. C. RANEY.

AUTOMATICALLY RECLOSING CIRCUIT BREAKER.

APPLICATION man JUNE 13. 1919.

1 63,814. Patented Dec. 28, 1920.

2 SHEETS-SHEET I.

Figmol @TLQQJW vA. TTORNE Y.

E. C. RANEY.

AUTOMATICALLY BECLOSING CIRCUIT BREAKER.

APPLICATION FILED JUNE 13. 1919.

2 SHEETS-SHEET 2.

INVENT OR.

A TTORNE Y.

UNITED STATES PATENT OFFICE.

ESTELL C. RANEY, 0F COLUMBIJ'S, OHIO, ASSIGNOR TO THE AUTOMATIC RECLOSING CIRCUIT BREAKER COMPANY, OF COLUMBUS, OHIO, A CORPORATION OF OHIO.

AUTOMATICALLY-RECLOSING CIRCUIT-BREAKER.

' Application filed June 13, 1919.

' To all to/mm it may concern:

Be it known that. I, ESTELL C. RANEY, a citizen of ,the United States of America, re-

siding at Columbus, in the county of Frank-,

It is particularly adapted to be used inconnecting two circuits which are supplied by current from independent sources at certain times, and on which at certain other times it is desirable to supply current to both sections from the same source. To meet these conditions, I have devised a breaker which will operate equally well whether it be energized from one section or the other, or both simultaneously.

My invention aims to provide a circuit breaker for connecting circuits or sections which will open uponshort-circuit or voltage failure, which will not close as long as there is a short-circuit in either section or circuit or abnormally low voltage on both, but

which will close when the short-circuit is removed from one section providing there is sufficient voltage on the other section, whether both sections or circuits are being independently fed or only one.

My circuit breaker mechanism is provided with a terminal connected to each circuit or section and a main contact element for bridging said terminals. This main contact element will open on short-circuit or voltage failure. However, Ihave provided a low resistance element that still bridges the terminals when the main contact element is open and I have provided a governing or trip coil of relatively high. resistance for the reclosing mechanism of the breaker which governing coil is connected to the center of the low resistance. The result of this structure is that when there isa short-circuit on either section or circuit, the greater portion of the current'will pass through the low resistance bridging element and the short-circuit and only a small portion will pass through the governing coil. WVhen the shortcircuit is removed .the increased resistance which results will render the governing coil subject to operation. If there is sufficient Specification of Letters Patent.

Patented Dec. 28, 1920.

Serial No. 303,923.

aggregate potential on the two circuits or sections, to operate the governing coil which is set for a certain voltage, it. will be immaterial whether the sections are independently fed or not and it will likewise be immaterial whether the potential of either section is greater than the other because, the governing coil being connected to the center of the low resistance bridging element, this governing coil will be equally influenced by current from either section. The result will be that the trip coil will be operated by the resultant potential at the juncture of the two sections.

Many other features of my apparatus are important and these will be mentioned as this description progresses. The preferred embodiment of my apparatus is shown in the accompanying drawings wherein similar characters of reference designate correin the open position.

Figs. 3 and 4 are simplified diagrammatic showings which more clearly illustrate the theory of-operation of my apparatus.

In the drawings, referring particularly to Figs. 1 and 2, I have shown sections A and B which are connected by a circuit breaker embodying a main movable contact member 1 designed to cooperate with spaced contact points 2 and 3. The movable member 1 is operated by an operating coil 4 through the medium of a plunger 5 and a lever 6. This operating coil 4 is under the control of an overload cut-out switch 7, which is in turn controlled by a coil 8, through the medium of a plunger 9.

In conjunction with the operating coil 4, I have provided a lockout mechanism designed to prevent reclosing of the brush 1 until a predetermined period has elapsed after opening and a predetermined voltage exists. This lockout mechanism comprises an arm 10 pivoted at 11 and provided with a spring 12 tending to pull it against contact 13. This arm 10 is forced open by a thrust member 14 on the contact 1 when such contact is bridging contact points 2 and 3. The arm 10 is provided with a keeper extension depending below its pivot, which keeper cooperates with a latch 15 subject to v and at all other times to make such resistance 20 a part of the operating circuit of the coil 4. The resistance 20 is of such value as to reduce the current in coil 1 to an amount which is sufficient to hold the breaker closed but not suflicient to permit the breaker to reclose.

Bridging the main contact of the circuit breaker are two equal resistances 21 and 22. At the juncture of resistances 21 and 22 is a connection 23 from which current" supplied to the operating coil 4 through wire 2 1, flexible connection 25 to contact 26, wire 27 to contact 13, and then either through resistance 20 or contact arm 10 to pivot 11, wire 28, through coil 4, wire 29 to wire 30. \Vith position of the parts as shown in Fig. 2, there is also a circuit from point 23 through wire 31, resistance 32, coil 16, wire 33, contact arm 18, to contact-35, through wire 30 to return side of line 36.

1 The operation may be described as fol ows:

With section A and section B in -normal condition, they will be connected-by the breaker .as shown in Fig. 1. In case either section becomes short-circuited or overloaded, an excessive current will pass through series coil 8. Plunger 9 will then be raised and engage cut-out switch 7 in such a man'- ner as to rotate it out of contact with point 26. This results in the denergization of operating coil 4 and the consequent opening of the breaker. The parts now assume position shown in Fig. 2. Immediately upon the removal of the overload, plunger 9 will drop back to original positoin and the contact arm 7 will again complete the circuit of the operating coil 1. The resistance 20 is of such value, however, that coil 4 will not be sufficiently energized toreclose the breaker until resistance 20 is again short-circuited by arm 10. Arm 10 is controlled by latch 15 which is released by action of coil 16 whenever its potential reaches the value for which it is set to operate.

The operation of coil 16 unlatches contact arm 10 which in turn rotates into con tact with pointl13, thereby forming a shortcircuit around resistance 20. Coil 4: will now be subject to full line potential and will be energized sufiiciently to close the breaker and the arts will againbe in position sh 'nn ig.1,

When the coil 4 is subjected to full line potential and moves the contact member 1 into closed position, the member 14 comes into contact with the member 10. However, this member 10 remains in contact with point 13 until the breaker is very nearly closed. In this position, the plunger of the coil 4 is very close to the stop in'the upper end of the coil housing and the magnetic pull in this position is very strong, even with a reduced current in operating coil 4. In practical operation, the inertia of the moving parts carries the breaker to fully closed position after the resistance is inserted in operating coil. Therefore, a slight amount of current in the coil 4 maintains enough magnetic attraction between the plunger of coil 4 and the stop in the upper end of the coil housing to maintain the breaker closed. It should further be borne in mind that the leverage arrangement of the mechanism is such that a very small up ward pressure from the operating plunger of coil 4 is sufiicient to exert considerable pressure in the main contact member 1 of the circuit breaker, owing to the angular relation between the lever arm 6 and the contact support member. The drawings illustrate this change of angle best by a comparison of Figs. 1 and 2. In comparing these figures, it will be noted that the angular relation between the lever arm 6 and the contact support member is considerably less in Fig. 2 with the breaker open than it is in Fig. 1 with the breaker closed and the center line of the arm 6 more nearly at a right angle to the contact member.

The setting of coil 16 is preferably made somewhat greater than fifty per cent. of normal line potential so that the breaker cannot possibly reclose while a short-circuit exists, but may reclose whenever the potential on one section is approximately normal and no short-circuit or extremely low resistance load exists on the other section. If both sections A and B are energized, the potential supplied to coil 16 will be the average potential of the sections A and B.

In order to clearly show that the breaker will not reclose while a short-circuit exists on either section, and that it may be set to reclose at various degrees of load resistance, I am giving a specific example in which is given,calculated values of potential which exist in various parts of the circuit under various conditions.

Referring to Fig. 4, let us assume the con-- dition in which a short-circuit exists between section A and ground return at point 36. Let us assume the potential existing between section B and return wire 36 to be 600 volts and resistances 21 and 22 to be of 10 ohms resistance each. Let us further assume that the potential coil 16 is set to operate at 310 volts and the combined resistance of the coil 16 and its protective resistance 32 have a combined resistance of 2,000 ohms. Also, that the operating coil at and its protective resistance 20 have a combined resistance of 2.000 ohms. It will be apparent that the combined resistance of the two paths through coil 16 and coil 4: between point 23 and wire 36 will have a combined resistance of 1,000 ohms. The currentwhich will be diverted from section 21 will be practically negligible so far as its effect upon the drop of potential across section .21 is concerned. \Vith the short-circuit of zero resistance between section A and wire 36, practically the entire 600 volts pressure through section B will be consumed in forcing a current through resistances 21. and 22. The value of this current will be 600 divided by 10 plus 10 or 30 amperes. Practically speaking, the drop of voltage between section B and point 23 will be 300 volts and the potential drop from point 23 through resistance 21, through section A, through short-circuit to wire 36 will be practically 300 volts. \Vith potential coil 16 adjusted at 310 volts it will be evident that the breaker cannot reclose until the resistance between section A and wire 36 increases to an amount sufiicient to cause a drop of potential between point 23 and wire 36 of 310 volts. This will means that at the point of operation the drop of potential be tween section B and point 23 can not exceed 290 volts. Similarly, a drop of potential between point 23 and section A cannot exceed 290 volts. In other words, the drop of potential through resistances 21 and 22 will be 580 volts and the difference between 580 and 600 or 20 volts must be produced by the current in passing through resistances 21 and 22 through the load circuit of section A. The value of this current will be equal to 580 divided by 20 or 29 am peres. Therefore, the load resistance between section A and wire 36 must have a minimum resistance value equal to 20 divided by 29 or .69 ohms, before the breaker will reclose.

Vith a load resistance less than the .69 ohms, the potential between point 23 and wire 36 will be insuflicient to close the breaker. However, a load resistance in excess of .69 ohms will produce a potential exceeding 310 volts between point 23 and wire 36 and the breaker will immediately reclose. This condition represents one of the possible conditions which exist in a network'distribution when section A may be supplied by current from one or more sources. The foregoing example is given under the assumption that section A, at the time being, was not energized from any other point except from section B. an other condition which may arise in the op eration of such a system would be the case in which section A was energized from another source besides its connection to section 13. Assuming again that the circuit breaker was open between section A and section B by an overload current flowing from section B into section it. or. vice versa. and in which case no short circuit exists and sections A and B are both energized from a separate source of supply. The closure of the breaker will then take place immediately after the expiration of the time interval. provided the average voltage between section A and section B is equal to the setting of the potential coil 16. That is. if potential coil 16 is set to operate at 310 volts. it will be necessary for the voltage of section B plus voltage of section A. divided by 2 to be equal to or in excess of 310 volts. Assuming the potential of section B at breaker to be 400 volts and voltage of section AS at breaker to be 300 volts. the resulting potential be tween point 23 and wire 36 will be 350 volts which would be sutiicient to operate coils 1.6 and 1 and would result in the closure of the breakerconnecting the two sections. Assuming that the voltage of section B was 400 and the voltage of section 11" only 200, the resulting potential between point 28 and wire 36 would be 300 volts which is below the assumed setting of coil 16 and the breaker would refuse to close under this condition.

It will be understood that coil 16 is pro vided with adjustments whereby it may be regulated to demand any desired potential between titty per cent. of normal voltage and normal voltage to cause its operation. This provides a circuit breaker which is very flexible in its operation and which can be used to tie two adjacent sections together very effectually when load conditions are normal and to disconnect them automatically when abnormal conditions arise. Another great advantage of this breaker when used as a sectionalizing breaker, lies in the fact that it will operate equally well when energized from either section or both sections simultaneously. As illustrated above. with section B energized from a distant source of supply, section A having no other source of supply except at section B. will automatically be connected to section B whenever the load resistance of section A is within the limits of operation of the breaker. The foregoing examples are taken from arbitrary values so far as resistances are concerned. to illustrate the principles of operation. These values may both be greater or less in actual operation, depending upon the apacity of the circuit to be protected.

It will be apparent that I have provided a novel type of circuit breaker. it is well adapted to connecting adjacent sections or circuits and will open automatically upon overload or short-circuit. Vhat is more important is that it will close automatically, but not untilshort-circuit conditions on cither section are removed. I am the first to provide an automatically reclosing circuit breaker which will operate equally well when connected in a circuit such that the clear of short circuits and the connected load resistance is at or above a predetermined minimum value.

2. An automatically reclosing sectionalizing circuit breaker comprising means for automatically connecting two circuit sections, said means beingoperative whenever either circuit is energized at approximately normal potential and the other section is clear of short circuits and the connected load resistance is at or above a predetermined minimum value, regardless of whether or not the other section is independently energized.

3. An automatically reclosing sectionalizing breaker comprising a 'main contact member for connecting two sections when in closed position, and mechanism for automatically closing said main contact member of such nature and so connected to both sections that it will be equally influenced by a given potential applied from either section and which will close said breaker when proper load conditions exist regardless of whether or not the other section is energized by current from another source.

4. An automatically reclosing sectionalizing breaker comprising a main contact member, means for automatically closing said main contact member, a resistance ele ment for bridging the gap between sections and limiting the flow of current between such sections when said main contact memher is in open position, said resistance element and said closing means being so connected that a given current passing through said resistance element will produce practically the same potential on the closing means when a given potentialis applied to either terminal and will effect operation of said closing means whenever a given potential is applied to'either terminal and the proper load conditions exist on the other section regardless of Whether or not a potential is applied to the other section from another source.

5. An automatically reclosing sectionalizing circuit breaker comprising terminals by which connection is made to each of two sections, a main contact member, means for closing said main contact member so as to permit a tree passage of current fromone section to the other, a resistance element connected between said breaker terminals so as to limit the passage of current from one section tothe other when the main contact is in open position, means for governing the said closing means. in response to a predetermined potential, and means whereby the said governing means will be equally influenced by a given potential when applied to either terminal.

6. An automatically reclosing sectionalizing breaker comprising a main contact member. means for automatically closing said main contact member, a resistance ele; ment for bridging the gap between sections and limiting the flow of current between such sections when said main contact member is in open position. said resistance element and said closing means being so connected that a given current passing through said resistance element will produce practically the same potential on the closing means when a given potential is applied to either terminal,

'7. An automatically reclosing sectionalizing breaker comprising a maiircontact to be placed between two sections, means responsive to overload or potential-failure for opening said main contact, means for auto matically closingsaid breaker in response to a predetermined potential, a limiting resistance between sections formed in two parts of substantially equal value, a switch in the circuit of said reclosing coil which is opened by the closing of said breaker, a latch automatically effective for maintaining said switch open, a trip coil for releas ing said latch to permit closing of said switch. a circuit for said trip coil comprising a path from the juncture of the parts of said limiting resistance to the opposite line whereby the trip coil will be operated to render the closing means operative by the resultant potential at said juncture due to the potential of both. irrespective of the individual potential of such sections.

8. An automatically reclosing sectionalizing breaker comprising a main contact member for connecting two sections when in closed position and mechanism for auto- 'matically closing said main contact member in response to potential from either section when the other section is not energized except from the first section.

9. An automatically reclosing sectionalizing breaker comprisng a main contact memher for connecting two sections, means responsive to overload or potential-failure for opening said main contact, means for automatically closing said contact member in response to a predetermined potential, means whereby said closing means will be energized at the same potential by the two sec tions when first one of said sections is energize-d at a certain voltage and the other section is energized at another voltage or vice versa.

10. An automatically reclosing sectionalizing breaker comprising a main contact member to be 'placed between two sections, and mechanism for automatically closing said main contact member, when both sections are independently energized, in response to the averages of the potentials of the two sections at the opposite terminals of the breaker whether the potential on both sections are equal or not.

11. An automatically reclosing sectionalizing breaker comprising a main contact member for connecting adjacent sections and means for closing said member, and an electrical control for said closing means of such form that it will respond to av definite potential and will operate whenever a predetermined aggregate potential exists on the sections connected by the breaker regardless of whether one section is energized from another source or both in varying degrees.

12. An automatically reclosing sectionalizing breaker comprising a circuit breaker switch and operating mechanism therefor comprising a reclosing coil, a potential coil for rendering said reclosing coil effective, a limiting resistance element connecting adjacent sections, and a connection between the center of said resistance element and the oppositel side of the line and running through said operating coil whereby said operating,

coil may be energized to close the breaker by current from either section.

13. An automatically reclosing sectionalizing circuit breaker comprising a main contact element, two terminals to be bridged by said element, a limiting resistance connected between said terminals, an operating coil for closing said main contact element, an overload device for opening said main contact element, a lookout mechanism for preventing reclosure of said element until proper conditions exist, a coil governing the said lockout mechanism, and connected at substantially the center of said limiting resistance, so that it will be equally energized by a current of a given potential at either terminal.

1 1. An automatically reclosing circuit breaker comprising a main contact member, two terminals adapted to be bridged by said member, means for closing said member and retaining it closed while normal conditions exist, means for opening said member upon overload or voltage-failure, means for rendering said closing means inoperative as long as a short-circuit of low resistance exists on the circut to which either of said terminals is connected, and means for rendering said closing means operative to close said breaker whenever said shortcircuit is removed and practically normal potential is restored to either one of the two terminals or to both terminals.

15. An automatically reclosing circuit breaker comprising a main contact member, two terminals adapted to be bridged by said member, and devices for closing said member and retaining it closed while normal conditions exist, preventing closure as long as a short-circuit of low resistance exists on the circuit to which either of said terminals is connected, and closing said member whenever said short-circuit is removed and practically normal potential is restored to either one of the two terminals or to both terminals.

16. An automatically reclosing circuit breaker comprising a main contact element for bridging two opposite terminals, means for closing said main contact element, means for opening the said main contact member in case of overload or voltage-failure, a resistance element connecting the two opposite terminals so as to allow a current of limited value to be shunted by the open contact member, and means governing the reclosing means, connected at substantially the middle point of said limiting resistance, said governing means having a high value of resistance relative to the limiting resistance, so that a very small portion of the current shunted around the open breaker and through a short-circuit will be diverted through said governing means.

17. An automatically reclosing circuit breaker comprising a main contact member, a coil for eiiecting automatic movement of said contact member into closed position, a means operative to subject said coil to a potential sufficient to close said member when line conditions are normal but operative after closure or when line conditions are abnormal and said member open, to subject said coil to a current of a value sufficient to maintain closure but less than that necessary to effect closure.

18. An automatically reclosing circuit breaker comprising a main contact member, a coil for closing said contact member, a resistance for limiting the current to said closing coil to a value sufficient to maintain the main contactclosed, but insuflicient to cause it to move from open position to closed position, a switch for bridging said resistance while the main contact is moving from the open to the closed position, means for locking the said switch in'the open position, a trip coil for releasing said locking means, and means for adjusting the setting of said trip coil so that it will operate at any chosen value of potential.

19. An automatically reclosing circuit breaker comprising a main contact member, porarily by-passed to permit the closing of a closing coil for effecting automatic movcthe main contact, said means being respon- 10 ment of. said contact member into closed posive in operation to a predetermined position means whereby the circuit in the clostential.

5 ing coil is limited to a value sufficient to In testimony whereof I hereby aflix my hold the main contact closed but insufficient signature. to effect its closure from the open position. means whereby said limiting means is tern ESTELL C. RANEY. 

